1. Field of the Invention
The present invention relates to an evaluating apparatus for acquiring information on a specimen, and more particularly to a cross section evaluating apparatus and a cross section evaluating method for processing and evaluating a cross section of a specimen of which state and shape vary according to a change in temperature.
2. Related Background Art
The demand for evaluation of a cross section or processing of a fine structure in organic materials, including bio-origin materials and plastics, is increasing together with the recent increase of functional devices.
As the principal methods of preparing a cross section, utilized for obtaining information on the structure of an organic material, there are known for example a cutting method with a blade, an embedding method in resin, an embedding method by freezing, a breaking method by freezing, an ion etching method etc., but, in case of observing the internal structure of an organic material with an optical microscope, there is usually adopted a method of embedding the organic material in a resin and cutting it with a microtome.
However, the observation with an optical microscope is limited to a macroscopic analysis of the cross section, and, since the cut-out position cannot be designated, a large amount of work has been necessary in repeating the cross-section preparing operation, in order to achieve observation and analysis of the structure of the designated position.
For this reason, there has recently been developed an FIB (Focused Ion Beam) apparatus as described in U.S. Pat. No. 5,504,340 by which a desired position can be processed. The FIB apparatus irradiates a specimen to be processed with a finely focused ion beam from an ion source, thereby achieving a processing operation such as etching. The etching technology with such an FIB apparatus is becoming more and more popular, and is currently widely utilized for a structural analysis and a defect analysis of a semiconductor material or the like, and for preparing a specimen for a transmission electron microscope.
However, in case the aforementioned conventional FIB apparatus is used for observation and analysis of the cross-sectional structure of a specimen of which the state or shape changes with the temperature, such as an organic material, the heat generated in the course of FIB processing causes a change in the temperature of the specimen, thereby varying the state or shape thereof, whereby the cross-sectional structure of the specimen cannot be exactly analyzed.
In consideration of the foregoing, WO03/032360A1 discloses an apparatus for evaluating the specimen using an FIB apparatus provided with means for maintaining a constant temperature of the specimen.
However, there is room for further improvement even in the evaluating apparatus disclosed in WO03/032360A1 from viewpoints of facilitating the evaluation of the specimen and enabling effective evaluation.